1. Field of the Invention
The present invention relates to a starter of the magnetic pinion shift type which shifts a pinion shifting member slidably supported on an output rotary shaft by sliding it by a shift lever connected with an electro-magnetic switch.
2. Description of Related Art
Heretofore, this type of starter has been a well known apparatus disclosed in such as Japanese Utility Model Application Laid-Open No. 63-71474 (1988). FIG. 1 is a sectional view illustrating a general configuration of this type of starter 1, and FIG. 2 is a perspective view illustrating how the parts of one portion thereof are integrated. An output rotary shaft 3 rotates according to torque of a direct current motor 2, and a pinion shifting member 4 is slidably fitted on the output rotary shaft 3. The pinion shifting member 4 is engaged with a ring gear of an engine (not shown), transmitting the torque being generated in the direct current motor 2 to the engine. Beneath the direct current motor 2, there is arranged an electro-magnetic switch 5 which slides the pinion shifting member 4 on the output rotary shaft 3 and connects a power source to the direct current motor 2. At the front end of the electro-magnetic switch 5, there are arranged a plunger 6 drawn by the electro-magnetic switch 5 and a hook 7 moving with the plunger 6. The hook 7 engages the lower end 8a of a shift lever 8 which slides the pinion shifting member 4 on the output rotary shaft 3. The upper end 8b of the shift lever 8 engages the pinion shifting member 4. The middle portion in the longitudinal direction of the shift lever 8 defines a swinging fulcrum 8c having roller-form projections on both sides. The front end of the starter 1 is covered with a front bracket 9. A cover 9a of the upper half portion of the front bracket 9 covers the front end of the direct current motor 2, and a cover 9b of the lower half portion covers the front end of the electro-magnetic switch 5. On the cover 9a of the upper half portion of the front bracket 9, there are provided, in the middle portion of the cover 9a, a bearing 10 supporting the front end of the output rotary shaft 3, and in the upper portion thereof, an opening 12 which opens upward so that a pinion 11 of the pinion shifting member 4 can be engaged with the ring gear of the engine in its full shifting position.
FIG. 3 is a perspective view seen from the inside of the middle portion of the front bracket 9. At a boundary between the cover 9a of the upper half portion and the cover 9b of the lower half portion of the front bracket 9, there is provided a lever box 13 which is surrounded by four walls and which has one open surface facing the inside of the starter and which houses the swinging fulcrum 8c of the shift lever 8 with the capability of swinging. At the upper wall 13a and the lower wall 13b of the lever box 13, there are provided notches 14 through which both arms of the shift lever 8 extend from the swinging fulcrum 8c toward their respective directions opposite to each other, respectively. Those arms of the shift lever 8 which have gone through those notches 14, then, go through the cover 9a of the upper half portion and the cover 9b of the lower half portion of the front bracket 9, respectively, and, as has been described above, the upper end 8b of the shift lever 8 engages the pinion shifting member 4, and the lower end 8a engages the hook 7 of the electro-magnetic switch 5. Between the front end of the electro-magnetic switch 5 and the cover 9b of the lower half of the front bracket 9, there is produced a space 16 for housing the shift lever 8.
A lever packing 15 comprised of a rubber plate whose front surface is coated with a steel plate is pressed onto the inner open surface 13c so as to close the lever box 13.
With most conventional starters the electro-magnetic switch 5 is provided in the upper portion thereof. In a vehicle in which the electro-magnetic switch 5 is provided in the lower portion of the starter as shown in FIG. 1, however, water enters from the opening 12 of the front bracket 9 which opens upward, as shwon in the arrows in FIG. 1. The water goes from internally of the cover 9a of the upper half portion of the front bracket 9 through the notches 14 of the lever box 13 to the space 16 formed between the cover 9b of the lower half potion of the front bracket 9 and the front end of the electro-magnetic switch 5. The water then, goes along the circumference of the plunger 6 and enters into the electro-magnetic switch 5, the water preventing the electro-magnetic switch 5 from performing its normal operation.
In order to prevent water from entering into the electro-magnetic switch 5, there is provided, in the lowest end of the cover 9b of the lower half portion of the front bracket 9, a hole 17 for draining water of a maze form which goes through windingly to the outside thereof. The hole for draining water which is provided in the lowest end of the front bracket 9, however, has a limitation in its size because of the strength of the bracket 9. Accordingly, in the case where a large amount of water enters from the opening 12 of the front bracket 9, it takes a long time until the water is completely drained from there.
Then, there exists a problem that the water filled in the space 16 of the front end of the electro-magnetic switch 5 enters into the electro-magnetic switch 5.